If your company is buried in paper, you may wonder how long you have to keep old records. There's no easy answer, according to Donald S. Skupsky, author of Recordkeeping Requirements. Here are some general guidelines, but Skupsky suggests checking the legal requirements of each state in which you conduct business and of any regulatory agency with which your company deals.

Source: Recordkeeping Requirements, by Donald S. Skupsky, Information Requirements Clearinghouse, Denver, 1994.
How long must I keep this stuff?
Federal tax returns 3 years 6 years
Payroll records 4 years 6 years
Account ledgers 3 years 6 years
Sales receipts 3 years 6 years